Apparatus for feeding pulverized fuel.



G. W. SHORT.

APPARATUS FOR FEEDING PULVERIZED FU EL.

APPLICATION HLED NOV. 24. 1913.

1,172,745. v v Patented Feb.22,1916.

F l l I? :l 1 i I i 1 l2 POWDERE-D CO AL.

WITNESSES INVENTOR Gaonaz. .W. SHORT M A 9%M THE COLUMBIA PLANOGRAPH co., WASHINGTON. n.

UNITED STATES PATENT OFFICE.

GEORGE w. SHORT, 0F SHARON," rnNnsYfovANIA.

APPARATUS ronrnnnme PULVERIZED FUE To all whom it may concern:

Be it known that I, GEORGE W. SHORT, a citizen of the United States, residing at Sharon, in the county of Mercer and State of Pennsylvania, have invented certain'new and useful Improvementsin Apparatus for Feeding Pulverized Fuel, of which the following is a specification.

This invention relates to apparatus for feeding pulverized fuel to furnaces, etc.

One of the purposes of the invention is the; provision of means whereby a fuel feed of this result; the most common being the einployment of a conveyer screw for feeding the coal into the blast pipe. In the passage of the coal along the conveyer pipe to the point of discharge therefrom there is a continual rising and slippingof the. coal on the f screw which results in a constant fluctuation- On the of discharge into the blast pipe. other hand, the prior attemptsof employing air to feed the fuel into the blast pipe have met'with no greater success. Where directl suction has been used it was found that the variation in the lift has given as unsatisfactory results as under the mechanicalprocess. In obtaining a uniform lift resort has been had to an air chamber n which the coal coming froma fixed point 18 fluffed and carried to the blast pipe by air. Under this method sufficient volume is. unobtainable in that impact instead of either suction orpressure alone is relied on.

In obtaining the desired result, I have provided means whereby the fuel is constantly maintained at a fixed level by gravity. From this point the fuel is drawn a fixed distance by a strong suction and then blown under high pressure into the blast pipe.

Specification of Letters Patent,

A still further end'whi'ch I obta'inb hi5 1 finely pulverized coal thancanj besuccessf" apparatus, is :the ability tofeedia more Patented'Feb. 22, 1916." m a I Applicationfiledfl'ovember 24,1913/ Seria1No.8G 2,717. l T

fully used, under the present. processes." By

eliminating atmospheric influences and relying entirely on direct and confined imf pelling means, I am able to use coal'running' 95 per cent. 100 200 mesh.

mesh: and-75 to 85 percent.

Another' purpose of the invention is the 1 employment of means, foraccoinplishing i the foregoing results, which are simple in construction and operation and require a eration. I I

Other'objects and purposes ofithe present invention will appear froin'an inspection of thedrawing, the description thereof and the I claims appended thereto, inwhich are particularly set forth the combination ofelements, arrangement of parts and specific structural details properlycomprised within the scope of the same.

z minimuniof attention and expense in its op- Referring now to the drawing in which is;

shown a preferred embodimentof my in-- vention, Figure I, is a. front elevation of.

my vapparatus showing the hopper, feed. chamber, vacuum arrangement thereon and.

connectionsleading into the blast pipe. Fig. j

II,is a side elevation on line Z'-Z' of Fig. I.

In the drawing, j in which like reference characters designate like parts, (1) is a hopper, which, in operation, is maintained well filled with pulverized :jfuel'for then present explanation, coal. Extending for-- wardly from the bottom of the rear side of' this hopper isthe bottom plate (2) which is inclined at an "angle of approximately degrees. The plate. (2) leads into a feed chamber (3). This chamber," which is equal' in'width to the bottom of the hopper, has.

its bottom, front and two sides inclosed.

which at. its upper end enters the central under portion of the vacuum chamberx('( Entering the rear end of the vacuum cham- I ber isan inlet nozzle (8). Air enters the '95, The rear wall"(4 of the chamber extends of approximately the same diameter as the pipe (6), extends from the forward end of the chamber (7) into a blast pipe (12). Leading from the inner central portion of the chamber (7) into the pipe (10) is a concentrating nozzle (11). The latter has its ends increasing in diameter from a contracted portion between sueh'ends; each end being that of the inlet nozzle (8), from. which it is separated by an intervening space, though alined and concentric therewith.

The blast pipe terminates in a burner nozzle (13) through which the coal and air is blown intothe furnace.

, My apparatus operates as follows: The hopper is kept well filled with pulverized coal. An air pressure of from five (5) to twenty-five (25) pounds is supplied to the pipe 9, while the air pressure in the blast pipe is about 12 oz. The coal slides from the hopper down the plate 2, into the feed chamber 3. The bafiie 4 checks the coal and maintains a normal level at approximately the line XX as shown in Fig. II. The high pressure air passing from the nozzle 8 into 11 creates a vacuum inthe surrounding portion of .chamber. 7 and the comminuted coal is sucked up to take the place of the exhausted air. It will be readily understood that as fast as coal is drawn 7 7 is driven into the concentrating nozzle 11,.

from the level XX, the coal in the hopper, impelled by gravity, slides into the feed chamber to maintain the level. The coal now drawn up the pipe 6 into the chamber and thence through the pipe 10 into the blast pipe 12, where the fuel is mixed with the proper quantity of air and blown. into the furnace.

From the foregoing, .it will be seen that the coal is first gravity fed, then lifted by Vacuum and finally air driven into the furnace. At the same time a constant force acts for a fixed distance in each of the several steps. 7

I have found that when the furnace is shut down for some time, the pulverized coal in the hopper and feed chamber tends to cake. I have overcome any diiiiculty in starting the flow by providing the air inlet (14:) in the rear of the hopper just above the bottom plate.

plate for controlling the flow ofsaid mateof a greater internal diameter than.

rial to maintain arpredetermined level of material in said feed chamber, an ejector nozzle above said feed chamber, a pipe connectingsaid ejector nozzle with said feed chamber, a blast pipe leading to a burner,

and a supply pipe from'said ejector to said.

blast pipe.

2.- In an apparatus of the class described.

in combination, a supply hopper, a feed chamber, an inclined floor leading from said supply hopper to. said feed chamber to permit material in said supply hopper to be;

fed by gravity to said feed chamber, a battle plate adjacent said feed chamber to control 5 the height of material in said feed chamber, an e ector nozzle above and operatively connected to said feed chamber to draw mate-- rial vertically from said feed chamber, a.

said delivery pipeterminating within said blast pipe.

3. An apparatus for feeding pulverized fuel to a furnace comprising in combination a fuel supply hopper provided with an inclinedfioor, afeed chamber adjacent theit" lower end of saidinclined floor, means to regulate the height of material within said feed chamber, a high pressure ejector above.

said feed chamber, a vertical pipe leading y from the upper portion of said feed chamber to said e ector, a burner nozzle, and

means for conducting material fromsaid:

ejector to the burner nozzle.

l. In an apparatus for feeding pulverized fuel to a furnace, the combination of a sup ply hopper, a feed chamber below said sup-v ply hopper, means to conduct material from said supply hopper to said feed chamber,

means to maintain a predetermined level of material within said feed chamber, a high pressure e ector nozzle above said. feedi chamber, a burner nozzle, and connections for delivering material from said e ector to said burner nozzle.

5. In a device of the character described. incombination, a supply hopper,;a feed-c chamber, means for conducting material bygravity from said supply hopperto said feed chamber, means for maintaining said material within said supply hopper at a predetermined height, devices for lifting saidfimaterial from said feed chamber by means of ascending currents of air ata pres sure less than atmospheric pressure, said last mentioned meansmcluding an e ector having provision for a high pressure air,

current, a burner nozzle, and a conduit leading from said e ector to said burner nozzle. 6. In an apparatus for feeding pulverized fuel to a blast furnace, the combination of asupply hopper, a feed chamber, means for maintaining material in said feed chamber at a predetermined level, anejector mounted having its end directed toward said burner above said feed chamber, a low pressure nozzle. \1 x o pipe from said ejector being operatively In testimony whereof I aifix my signature,

connected With the upper portion of said in presence of two Witnesses. 1

feed chamber, a burner nozzle, a blast pipe GEORGE W. SHORT. leading to said burner nozzle, and a delivery Witnesses: I a pipe leading from said. ejector nozzle to sub- KATHERINE BURKE,

stantially the middle ofsaid blast pipe and EUGENE E, ANDERSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

7 Washington, D. G. V a 

